Like you said, GIGO, but I can't say I'm familiar with any csv looking like that. Maybe I'm living a lucky life, but true null would generally be an empty string, which of course would still be less than ideal. From a general csv perspective, NULL without quotes is still a string.
If "NULL" string, then lord help us, but I would be inclined to handle it as defined unless instructed otherwise. I guess it's up to the dev to point it out and not everyone cares enough to do so. My point is these things should be caught early.
I'll admit I'm much more versed in mysql than postgres.
NULL != 'NULL'
How do devs make this mistake
Thought it was interesting that no one mentioned Terraform or OpenTofu. Then checked the community I was in.
I don't know anything about economics but this is an interesting and recent Chapo podcast on the topic: https://youtu.be/rq5vxvS615Y
Iirc they say putting an embargo on countries will cause a cascade with all banks that use USD. They extend this to suggest that the US has sanctioned a third of the planet overall.